Detection device, display device, and electronic apparatus

ABSTRACT

A detection device includes a substrate, first electrodes, second electrodes, and a conductor. The substrate has a first surface and a second surface opposite to the first surface. The first electrodes are provided in a display area of the substrate and detect the position of an object being in contact with or in proximity to the first surface side of the substrate or pressure of the object being in contact with the first surface side. The second electrodes are provided along at least one side of the outer periphery of the display area. The conductor is provided on the second surface side of the substrate apart from the substrate and generates an electrostatic capacitor between the conductor and the second electrodes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/357,666, filed on Nov. 21, 2016, which application claims priorityfrom Japanese Application No. 2016-045844, filed on Mar. 9, 2016, thecontents of which are incorporated by reference herein in its entirety.

BACKGROUND 1. Technical Field

The present invention relates to a detection device, a display device,and an electronic apparatus.

2. Description of the Related Art

Touch detection devices that can detect an external proximate object,which are what is called a touch panel, have recently been attractingattention. Touch panels are mounted on or integrated with a displaydevice, such as a liquid crystal display device, to be used as displaydevices with a touch detection function. Some types of display deviceswith a touch detection function are known, including display devicesprovided with a capacitance touch sensor. Japanese Patent ApplicationLaid-open Publication No. 2009-244958 (JP-A-2009-244958) describes adisplay device with a touch sensor including detection electrodes for asensor in a frame area of a TFT substrate. The frame area surrounding adisplay area is provided with a plurality of detection electrodes for asensor individually separated from one another.

Japanese Patent Application Laid-open Publication No. 2000-66837(JP-A-2000-66837) describes a pressure detecting digitizer that includesliquid crystal display cells, and gate lines and drain lines provided inmutually intersecting directions. The pressure detecting digitizerdisclosed in JP-A-2000-66837 detects pressure applied to a liquidcrystal display panel based on capacitance changes of the liquid crystaldisplay cells provided at respective intersections of the gate lines andthe drain lines.

In the display device with a touch sensor described in JP-A-2009-244958,the detection electrodes for a sensor are provided as a group ofindividual electrodes and allocated to operation buttons correspondingto various functions of a display application, for example.JP-A-2009-244958 has no description of pressure detection. When thepressure detecting digitizer disclosed in JP-A-2000-66837 receives inputperformed at a plurality of positions on the liquid crystal displaypanel, the pressure detecting digitizer may possibly have difficulty indetecting accurate input positions and magnitude of pressure.

For the foregoing reasons, there is a need for a detection device, adisplay device, and an electronic apparatus that can accurately detectpressure.

SUMMARY

According to an aspect, a detection device includes a substrate having afirst surface and a second surface opposite to the first surface, firstelectrodes that are provided in a display area of the substrate and thatdetect a position of an object being in contact with or in proximity tothe first surface side of the substrate or pressure of the object beingin contact with the first surface side, a plurality of second electrodesprovided along at least one side of an outer periphery of the displayarea, and a conductor that is provided on the second surface side of thesubstrate apart from the substrate and that generates an electrostaticcapacitor between the conductor and the second electrodes.

According to another aspect, display device includes the detectiondevice described above, a plurality of pixel electrodes facing the firstelectrodes and arranged in a matrix, and a display function layer thatperforms an image display function in the display area.

According to another aspect, an electronic apparatus includes thedetection device described above, and a housing that accommodates thedetection device. The housing includes the conductor.

According to another aspect, an electronic apparatus includes thedisplay device described above, and a housing that accommodates thedisplay device. The housing includes the conductor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an exemplary configuration of a displaydevice with a touch detection function according to a first embodiment;

FIG. 2 is an explanatory diagram for explaining a basic principle ofmutual capacitance touch detection and illustrates a state where afinger is neither in contact with nor in proximity to a detectionelectrode;

FIG. 3 is an explanatory diagram of an example of a fringing electricfield in the state where a finger is neither in contact with nor inproximity to the detection electrode as illustrated in FIG. 2;

FIG. 4 is an explanatory diagram of an example of an equivalent circuitin the state where a finger is neither in contact with nor in proximityto the detection electrode as illustrated in FIG. 2;

FIG. 5 is an explanatory diagram for explaining the basic principle ofmutual capacitance touch detection and illustrates a state where afinger is in contact with or in proximity to the detection electrode;

FIG. 6 is an explanatory diagram of an example of a fringing electricfield in the state where a finger is in contact with or in proximity tothe detection electrode as illustrated in FIG. 5;

FIG. 7 is an explanatory diagram of an example of the equivalent circuitin the state where a finger is in contact with or in proximity to thedetection electrode as illustrated in FIG. 5;

FIG. 8 is a diagram of an example of waveforms of a drive signal and afirst detection signal in mutual capacitance touch detection;

FIG. 9 is an explanatory diagram of an example of the equivalent circuitin self-capacitance touch detection;

FIG. 10 is a diagram of an example of waveforms of a drive signal and asecond detection signal in self-capacitance touch detection;

FIG. 11 is a sectional view of a schematic sectional structure of anelectronic apparatus including the display device with a touch detectionfunction;

FIG. 12 is a sectional view of a schematic sectional structure of theelectronic apparatus according to a first modification;

FIG. 13 is a sectional view of a schematic sectional structure of theelectronic apparatus according to a second modification;

FIG. 14 is a sectional view of a schematic sectional structure of thedisplay device with a touch detection function according to the firstembodiment;

FIG. 15 is a plan view schematically illustrating a first substrate ofthe display device with a touch detection function;

FIG. 16 is a plan view schematically illustrating a second substrate ofthe display device with a touch detection function;

FIG. 17 is a circuit diagram of a pixel array in a display unit with atouch detection function according to the first embodiment;

FIG. 18 is a perspective view of an exemplary configuration of driveelectrodes and first detection electrodes in the display unit with atouch detection function according to the first embodiment;

FIG. 19 is an explanatory diagram for explaining pressure detectionperformed by the display device with a touch detection functionaccording to the first embodiment;

FIG. 20 is a schematic plan view illustrating the drive electrodes andsecond detection electrodes according to the first embodiment in anenlarged manner;

FIG. 21 is a sectional view along line XXI-XXI′ in FIG. 20;

FIG. 22 is a timing waveform diagram of an exemplary operation performedby the display device with a touch detection function according to thefirst embodiment;

FIG. 23 is a schematic sectional view schematically illustrating asectional structure of the display device with a touch detectionfunction according to a second embodiment;

FIG. 24 is a schematic plan view illustrating the drive electrodes andthe second detection electrodes according to a third embodiment in anenlarged manner;

FIG. 25 is a sectional view along line XXV-XXV′ in FIG. 24;

FIG. 26 is a plan view of the first detection electrodes of the displaydevice with a touch detection function according to the thirdembodiment;

FIG. 27 is a perspective view for schematically explaining a fringingelectric field generated between the drive electrode and frame wire;

FIG. 28 is a plan view schematically illustrating the first substrate ofthe display device with a touch detection function according to a fourthembodiment;

FIG. 29 is a plan view schematically illustrating the second substrateof the display device with a touch detection function according to thefourth embodiment; and

FIG. 30 is a schematic plan view illustrating the drive electrodes andthe second detection electrodes according to the fourth embodiment in anenlarged manner.

DETAILED DESCRIPTION

Embodiments for carrying out the present invention will be described indetail with reference to the drawings. The present invention will not belimited to the description of the embodiments given below. Componentsdescribed below include those easily conceivable by those skilled in theart, and those substantially the same. Moreover, the componentsdescribed below can be combined as appropriate. The disclosure is merelyan example, and the present invention naturally encompasses anappropriate modification maintaining the gist of the invention, which iseasily conceivable by those skilled in the art. To further clarify thedescription, a width, a thickness, a shape, and the like of eachcomponent may be schematically illustrated in the drawings as comparedwith an actual aspect. However, this is merely an example, andinterpretation of the invention is not limited thereto. The same elementas that described in the drawing that has already been discussed isdenoted by the same reference numeral through the description and thedrawings, and detailed description thereof will not be repeated in somecases where appropriate.

First Embodiment

FIG. 1 is a block diagram illustrating a configuration example of adisplay device with a touch detection function according to a firstembodiment. As illustrated in FIG. 1, the display device with a touchdetection function 1 includes a display unit with a touch detectionfunction 10, a controller 11, a gate driver 12, a source driver 13, adrive electrode driver 14, and a detector 40. The display device with atouch detection function 1 is a display device in which the display unitwith a touch detection function 10 incorporates a touch detectionfunction. The display unit with a touch detection function 10 is adevice configured by integrating a display panel 20 using liquid crystaldisplay elements as display elements and a touch panel 30 serving as adetection device for detecting a touch input. The display unit with atouch detection function 10 may be what is called an on-cell deviceconfigured by mounting the touch panel 30 on the display panel 20. Thedisplay panel 20 may be an organic electroluminescent (EL) displaypanel.

The display panel 20 is an element that performs display by sequentiallyscanning one horizontal line at a time according to a scan signal Vscansupplied from the gate driver 12, as will be described later. Thecontroller 11 is a circuit that supplies a control signal to each of thegate driver 12, the source driver 13, the drive electrode driver 14, andthe detector 40 based on an externally supplied video signal Vdisp, andthus controls these drivers and the detector so as to operate them insynchronization with one another.

The gate driver 12 has a function to sequentially select one horizontalline to be driven to perform display of the display unit with a touchdetection function 10, based on the control signal supplied from thecontroller 11.

The source driver 13 is a circuit that supplies a pixel signal Vpix toeach sub-pixel SPix (described later) of the display unit with a touchdetection function 10, based on the control signal supplied from thecontroller 11.

The drive electrode driver 14 is a circuit that supplies a first drivesignal Vcom to a drive electrode COML (described later) of the displayunit with a touch detection function 10, based on the control signalsupplied from the controller 11.

The touch panel 30 operates based on the basic principle of capacitancetouch detection, and performs a touch detection operation using a mutualcapacitance method to detect contact or proximity of an externalconductor with a display area. The touchscreen 30 may perform the touchdetection operation using a self-capacitance method.

The detector 40 is a circuit that detects whether the touch panel 30 istouched, based on the control signal supplied from the controller 11 anda first detection signal Vdet1 supplied from the touch panel 30. Whenthe touch panel 30 is touched, the detector 40 obtains, for example,coordinates of the touch input. The detector 40 includes a detectionsignal amplifier 42, an analog-to-digital (A/D) converter 43, a signalprocessor 44, and a coordinate extractor 45. A detection timingcontroller 46 controls the A/D converter 43, the signal processor 44,and the coordinate extractor 45 so as to operate them in synchronizationwith one another, based on the control signal supplied from thecontroller 11.

The detector 40 also includes a second detection electrode driver 48.The second detection electrode driver 48 is a circuit that supplies asecond drive signal Vd to a second detection electrode 23 (describedlater) when pressure applied to the display unit with a touch detectionfunction 10 is detected. The detector 40 detects the pressure applied tothe display unit with a touch detection function 10 based on a seconddetection signal Vdet2 supplied from the second detection electrode 23.

As described above, the touch panel 30 operates based on the basicprinciple of the capacitance touch detection. The following describesthe basic principle of the touch detection using the mutual capacitancemethod performed by the display device with a touch detection function 1of the present embodiment, with reference to FIGS. 2 to 8. FIG. 2 is anexplanatory diagram for explaining the basic principle of the mutualcapacitance touch detection, the diagram illustrating a state where afinger is neither in contact with nor in proximity to a detectionelectrode. FIG. 3 is explanatory diagram illustrating an example of afringing electric field in the state illustrated in FIG. 2 where thefinger is neither in contact with nor in proximity to the detectionelectrode. FIG. 4 is an explanatory diagram illustrating an example ofan equivalent circuit in the state illustrated in FIG. 2 where thefinger is neither in contact with nor in proximity to the detectionelectrode. FIG. 5 is an explanatory diagram for explaining the basicprinciple of the mutual capacitance touch detection, the diagramillustrating a state where the finger is in contact with or in proximityto the detection electrode. FIG. 6 is explanatory diagram illustratingan example of the fringing electric field in the state illustrated inFIG. 5 where the finger is in contact with or in proximity to thedetection electrode. FIG. 7 is an explanatory diagram illustrating anexample of the equivalent circuit in the state illustrated in FIG. 5where the finger is in contact with or in proximity to the detectionelectrode. FIG. 8 is a diagram illustrating an example of waveforms ofthe drive signal and the first detection signal. Although the followingdescribes the case where the finger is in contact with or in proximityto the detection electrode, an object being in contact with or inproximity to the detection electrode is not limited to the finger, but,for example, an object including a conductor, such as a stylus pen maybe in contact with or in proximity to the detection electrode.

For example, as illustrated in FIG. 2, a capacitive element C1 includesa pair of electrodes, that is, a drive electrode E1 and a detectionelectrode E2 that are arranged opposite to each other with a dielectricmaterial D interposed therebetween. In the capacitive element C1, linesof electric force (not illustrated) are generated between oppositesurfaces of the drive electrode E1 and the detection electrode E2, andin addition, as illustrated in FIG. 3, a fringing electric field Ef thatextends from ends of the drive electrode E1 toward the upper surface ofthe detection electrode E2 is generated. As illustrated in FIG. 4, thecapacitive element C1 is coupled, at one end thereof, to analternating-current signal source (drive signal source) S, and coupled,at the other end thereof, to a voltage detector DET. The voltagedetector DET is, for example, an integration circuit included in thedetection signal amplifier 42 illustrated in FIG. 1.

Applying an alternating-current rectangular wave Sg having apredetermined frequency (for example, approximately several kHz toseveral hundred kHz) from the alternating-current signal source S to thedrive electrode E1 (one end of the capacitive element C1) causes anoutput waveform (first detection signal Vdet1) illustrated in FIG. 8 tooccur through the voltage detector DET coupled to the detectionelectrode E2 side (the other end of the capacitive element C1). Thealternating-current rectangular wave Sg corresponds to the first drivesignal Vcom supplied from the drive electrode driver 14.

In the state (non-contact state) where the finger is neither in contactwith nor in proximity to the detection electrode, a current I₀corresponding to the capacitance value of the capacitive element C1flows in association with charge and discharge of the capacitive elementC1, as illustrated in FIG. 4. The voltage detector DET illustrated inFIG. 4 converts a variation in the current I₀ corresponding to thealternating-current rectangular wave Sg into a variation in voltage(waveform V₀ of a solid line (refer to FIG. 8)).

In the state (contact state) where the finger is in contact with or inproximity to the detection electrode, an electrostatic capacitor C2generated by the finger is in contact with or in proximity to thedetection electrode E2, as illustrated in FIG. 5. This causes aconductor E3 (finger) to shield the fringing electric field Ef locatedbetween the drive electrode E1 and the detection electrode E2, asillustrated in FIG. 6. This, in turn, causes the capacitive element C1to act as a capacitive element C having a smaller capacitance value thanthat of the non-contact state, as illustrated in FIG. 7. Referring tothe equivalent circuit illustrated in FIG. 7, a current I₁ flows in thecapacitive element C1′. As illustrated in FIG. 8, the voltage detectorDET converts a variation in the current I₁ corresponding to thealternating-current rectangular wave Sg into a variation in voltage(waveform V₁ of a dotted line). In this case, the waveform V₁ has asmaller amplitude than the above-mentioned waveform V₀. As a result, anabsolute value |ΔV| of a voltage difference between the waveform V₀ andthe waveform V₁ changes according to an influence of the conductor E3,such as the finger, coming into contact with or proximity to thedetection electrode from the outside. To accurately detect the absolutevalue |ΔV| of the voltage difference between the waveform V₀ and thewaveform V₁, the voltage detector DET preferably performs an operationincluding a period RESET during which the charge or discharge of thecapacitor is reset by switching in the circuit in accordance with thefrequency of the alternating-current rectangular wave Sg.

The touch panel 30 illustrated in FIG. 1 is configured to perform thetouch detection using the mutual capacitance method by sequentiallyscanning one detection block at a time according to the first drivesignal Vcom supplied from the drive electrode driver 14.

The touch panel 30 is configured to output the first detection signalVdet1 from a plurality of first detection electrodes TDL (describedlater) through the voltage detector DET illustrated in FIG. 4 or 7 on adetection-block-by-detection-block basis. The first detection signalVdet1 is supplied to the detection signal amplifier 42 of the detector40.

The detection signal amplifier 42 amplifies the first detection signalVdet1 supplied from the touch panel 30. The detection signal amplifier42 may include an analog low-pass filter (LPF), that is, an analogfilter passing low-frequency components that removes high-frequencycomponents (noise components) from the first detection signal Vdet1, andoutputs the result.

The A/D converter 43 samples each analog signal output from thedetection signal amplifier 42 at intervals synchronized with the firstdrive signal Vcom, and converts the sampled analog signal into a digitalsignal.

The signal processor 44 includes a digital filter that reduces frequencycomponents (noise components) included in the output signal of the A/Dconverter 43 other than that of the frequency at which the first drivesignal Vcom has been sampled. The signal processor 44 is a logic circuitthat detects, based on the output signal of the A/D converter 43,whether the touchscreen 30 is touched. The signal processor 44 performsprocessing to extract only a difference in detection signal caused bythe finger. This signal of difference caused by the finger is obtainedas the absolute value |ΔV| of the difference between the waveform V₀ andthe waveform V₁ described above. The signal processor 44 may perform acalculation of averaging the absolute values |ΔV| for one detectionblock to obtain the average value of the absolute values |ΔV|. Thisallows the signal processor 44 to reduce the influence of the noise. Thesignal processor 44 compares the detected signal of difference caused bythe finger with a predetermined threshold voltage, and, if the signal ofdifference is lower than the threshold voltage, the signal processor 44determines that the state is the non-contact state of the externalproximate object. The signal processor 44 compares the detected signalof difference caused by the finger with the predetermined thresholdvoltage, and, if the signal of difference is equal to or higher than thethreshold voltage, the signal processor 44 determines that the state isthe contact state of the external proximate object. The detector 40 canperform the touch detection in this manner.

The coordinate extractor 45 is a logic circuit that obtains touch panelcoordinates of a touch when the touch is detected by the signalprocessor 44. The coordinate extractor 45 outputs the touch panelcoordinates as a detection signal output Vout. As described above, thedisplay device with a touch detection function 1 of the presentembodiment can detect the touch panel coordinates of a position ofcontact or proximity of the conductor, such as the finger, based on thebasic principle of the touch detection using the mutual capacitancemethod.

The following describes the basic principle of the touch detection usingthe self-capacitance method, with reference to FIGS. 9 and 10. FIG. 9 isan explanatory diagram illustrating an example of an equivalent circuitfor the self-capacitance touch detection. FIG. 10 is a diagramillustrating an example of waveforms of the drive signal and the seconddetection signal of the self-capacitance touch detection.

As illustrated in FIG. 9, the voltage detector DET is coupled to thedetection electrode E2. The voltage detector DET is a detection circuitincluding an imaginarily short-circuited operational amplifier. When thealternating-current rectangular wave Sg having the predeterminedfrequency (such as approximately several kHz to several hundred kHz) isapplied to a non-inverting input part (+), the alternating-currentrectangular wave Sg having the same potential is applied to thedetection electrode E2.

In the state (non-contact state) where the conductor, such as thefinger, is neither in contact with nor in proximity to the detectionelectrode, a current corresponding to a capacitance Cx1 possessed by thedetection electrode E2 flows. The voltage detector DET converts avariation in the current corresponding to the alternating-currentrectangular wave Sg into a variation in voltage (waveform V₃ of a solidline (refer to FIG. 10)). In the state (contact state) where theconductor, such as the finger, is in contact with or in proximity to thedetection electrode, a capacitance Cx2 generated by the finger proximateto the detection electrode E2 is added to the capacitance Cx1 possessedby the detection electrode E2, and a current corresponding to acapacitance (Cx1+Cx2) increased from the capacitance of the non-contactstate flows. The voltage detector DET converts the variation in thecurrent corresponding to the alternating-current rectangular wave Sginto a variation in voltage (waveform V₂ of a dotted line (refer to FIG.10)). In this case, the waveform V₂ has a larger amplitude than thewaveform V₃ described above. As a result, the absolute value |ΔV| of avoltage difference between the waveform V₂ and the waveform V₃ changesaccording to the influence of the conductor, such as the finger, cominginto contact with or proximity to the detection electrode from theoutside. A switch SW is placed in the ON (open) state when the touchdetection is performed, and is placed in the OFF (closed) state toperform a reset operation of the voltage detector DET when the touchdetection is not performed.

The detection signal amplifier 42 amplifies the second detection signalVdet2 supplied from the touch panel 30. The A/D converter 43 sampleseach analog signal output from the detection signal amplifier 42, andconverts the sampled analog signal into a digital signal. The signalprocessor 44 calculates the absolute value |ΔV| of the differencebetween the waveform V₂ and the waveform V₃ based on the signal suppliedfrom the A/D converter 43. The signal processor 44 compares the detectedsignal of difference (absolute value |ΔV|) caused by the finger with thepredetermined threshold voltage, and, if the signal of difference islower than the threshold voltage, the signal processor 44 determinesthat the state is the non-contact state of the external proximateobject. The signal processor 44 compares the detected signal ofdifference (absolute value |ΔV|) caused by the finger with thepredetermined threshold voltage, and, if the signal of difference isequal to or higher than the threshold voltage, the signal processor 44determines that the state is the contact state of the external proximateobject. The coordinate extractor 45 calculates the touch panelcoordinates, and outputs the results as the detection signal outputVout. In this manner, the detector 40 can perform the touch detectionbased on the basic principle of the self-capacitance touch detection.

The voltage detector DET may be used to perform both the mutualcapacitance touch detection and the self-capacitance touch detection. Inthis case, switching is made such that the non-inverting input part (+)is supplied with a reference voltage having a fixed potential when themutual capacitance touch detection is performed, and the non-invertinginput part (+) is supplied with the alternating-current rectangular waveSg (first drive signal Vcom) when the self-capacitance touch detectionis performed.

The above has described the detection of the external proximate objectwhen the finger is in contact with or in proximity to the detectionelectrode, using FIGS. 9 and 10. The pressure applied to the inputsurface can be detected based on the detection principle of theself-capacitance method described above, by providing a conductor facingthe detection electrode E2. In this case, the distance between thedetection electrode E2 and the conductor changes with the pressureapplied to the input surface of the display unit with a touch detectionfunction 10, and the capacitance generated between the detectionelectrode E2 and the conductor changes. The touchscreen 30 outputs thesecond detection signal Vdet2 corresponding to this capacitance changeto the detection signal amplifier 42. The detection signal amplifier 42,the A/D converter 43, and the signal processor 44 perform the signalprocessing described above to calculate the absolute value |ΔV| of thedifference between the waveform V₂ and the waveform V₃. The distancebetween the detection electrode E2 and the conductor is obtained basedon the absolute value |ΔV|. Thereby, the pressure applied to the inputsurface is calculated. The coordinate extractor 45 calculates thepressure on the input position from a distribution of the pressureapplied to the input surface and the touch panel coordinates obtained bythe touch detection. The coordinate extractor 45 then outputs theinformation on the pressure.

FIG. 11 is a sectional view illustrating a schematic sectional structureof an electronic apparatus including the display device with a touchdetection function. An electronic apparatus 100 includes a cover member101, the display device with a touch detection function 1, a backlight102, and a housing 103. The cover member 101 is a protective member forprotecting the display device with a touch detection function 1, and maybe, for example, a light-transmitting glass substrate or a film-likebase material containing a resin material or the like. A surface on oneside of the cover member 101 serves as an input surface 101 a for thefinger or the like to perform an input operation by being in contacttherewith or in proximity thereto. The display device with a touchdetection function 1 includes a pixel substrate 2 (described later) anda counter substrate 3. The counter substrate 3 is provided on the pixelsubstrate 2, and is disposed on the other side of the cover member 101,that is, on a surface thereof opposite to the input surface 101 a.

The backlight 102 is provided on a side of the display device with atouch detection function 1 opposite to the cover member 101. Thebacklight 102 may be bonded onto the lower surface side of the pixelsubstrate 2, or may be disposed to the pixel substrate 2 with apredetermined gap provided therebetween. The backlight 102 includes alight source of, for example, light emitting diodes (LEDs), and emitslight from the light source toward the pixel substrate 2. The light fromthe backlight 102 passes through the pixel substrate 2, and switching isperformed between a portion shielding the light to prevent it fromexiting and a portion allowing the light to exit according to the stateof a liquid crystal at each location of the portions so that an image isdisplayed on the input surface 101 a of the cover member 101. Thebacklight 102 can employ a known illumination unit, and can have variousconfigurations. If the display panel 20 of the display device with atouch detection function 1 is a reflective liquid crystal displaydevice, the backlight 102 need not be provided. In the reflective liquidcrystal display device, the pixel substrate 2 is provided withreflective electrodes, and light coming in from the cover member 101 isreflected by the reflective electrodes, and reaches an eye of anobserver through the cover member 101. A front light may be providedinstead of the backlight 102.

The housing 103 is a box-like member having an opening at an upperportion thereof, and is provided with the cover member 101 so as tocover the opening of the housing 103. An internal space formed by thehousing 103 and the cover member 101 incorporates, for example, thedisplay device with a touch detection function 1 and the backlight 102.As illustrated in FIG. 11, the display device with a touch detectionfunction 1 and the backlight 102 are disposed on the cover member 101side, and a space 110 is provided between the backlight 102 and thebottom of the housing 103. An electrically conductive material, such asa metal, is used for the housing 103, and the bottom of the housing 103serves as a conductor 104 facing the second detection electrode 23 (notillustrated) of the display device with a touch detection function 1.The housing 103 is electrically coupled to the ground so as to beearthed. The configuration described above generates a capacitance C3between the second detection electrode 23 (not illustrated) of thedisplay device with a touch detection function 1 and the conductor 104.

When the pressure is applied to the input surface 101 a, the pixelsubstrate 2 and the counter substrate 3 are deformed so as to slightlybend together with the cover member 101 toward the bottom of the housing103. The display device with a touch detection function 1 detects achange in the capacitance C3 based on the detection principle of theself-capacitance method described above so as to obtain the amount ofbend of the cover member 101, the display device with a touch detectionfunction 1, and the backlight 102. Thereby, the pressure applied to theinput surface 101 a is obtained.

The space 110 between the backlight 102 and the bottom of the housing103 may be provided with an elastic material, such as sponge or elasticrubber, that is deformable in response to the applied pressure. Thehousing 103 is not limited to being made of the electrically conductivematerial, such as a metal, but may be made of an insulating materialsuch as a resin. In this case, at least the bottom of the housing 103may be provided with a metal layer so as to form the conductor 104.

FIG. 12 is a sectional view of a schematic sectional structure of theelectronic apparatus according to a first modification. The presentmodification includes a display device housing 107. The cover member 101is provided so as to cover the opening of the display device housing107. The display device with a touch detection function 1 and thebacklight 102 are accommodated in the internal space formed by thedisplay device housing 107 and the cover member 101. The display devicewith a touch detection function 1 is provided on the surface of thecover member 101 opposite to the input surface 101 a. The backlight 102is provided on the bottom of the display device housing 107. A spacer106 is provided between the display device with a touch detectionfunction 1 and the backlight 102 to form the space 110 between thedisplay device with a touch detection function 1 and the backlight 102.The display device housing 107 is fixed to the housing 103 of anelectronic apparatus 100A. With this configuration, the display devicehousing 107, the cover member 101, the display device with a touchdetection function 1, and the backlight 102 are integrally included inthe electronic apparatus 100A.

The display device housing 107 according to the present modification ismade of an electrically conductive material, such as a metal. With thisstructure, the bottom of the display device housing 107 functions as theconductor 104. The display device housing 107 is electrically coupled tothe ground. With this configuration, a capacitor C4 is generated betweenthe conductor 104 and the second detection electrodes 23 (notillustrated) of the display device with a touch detection function 1.The display device with a touch detection function 1 detects a change inthe capacitor C4 based on the detection principle of theself-capacitance method, thereby detecting pressure applied to the inputsurface 101 a.

While the display device housing 107 according to the presentmodification is made of an electrically conductive material, such as ametal, and the bottom thereof functions as the conductor 104, thestructure of the display device housing 107 is not limited thereto. Thedisplay device housing 107 may be made of an insulating material, suchas a resin material, and a metal layer may be provided to at least thebottom of the display device housing 107 to serve as the conductor 104.A metal layer may be provided to the lower surface (surface facing thebottom of the display device housing 107) of the backlight 102. Whilethe display device housing 107 is fixed on the housing 103 of theelectronic apparatus 100A, the fixing structure is not limited thereto.The cover member 101, for example, may be fixed to the housing 103.

FIG. 13 is a sectional view of a schematic sectional structure of theelectronic apparatus according to a second modification. In anelectronic apparatus 100B according to the present modification, thedisplay device with a touch detection function 1 and the backlight 102are accommodated in the internal space formed by the display devicehousing 107 and the cover member 101. The display device with a touchdetection function 1 is provided on the surface of the cover member 101opposite to the input surface 101 a. The backlight 102 is provided onthe surface of the display device with a touch detection function 1opposite to the cover member 101. The spacer 106 is provided between thebacklight 102 and the display device housing 107 to form the space 110between the backlight 102 and the display device housing 107.

Also in the present modification, the bottom of the display devicehousing 107 serves as the conductor 104, and a capacitance C5 isgenerated between the conductor 104 and the detection electrode (notillustrated) of the display device with a touch detection function 1.The display device with a touch detection function 1 can detect thepressure applied to the input surface 101 a by detecting a change in thecapacitance C5 based on the detection principle of the self-capacitancemethod described above.

The following describes a configuration example of the display devicewith a touch detection function 1. FIG. 14 is a sectional viewillustrating a schematic sectional structure of the display device witha touch detection function according to the first embodiment. FIG. 15 isa plan view schematically illustrating a first substrate of the displaydevice with a touch detection function. FIG. 16 is a plan viewschematically illustrating a second substrate of the display device witha touch detection function.

As illustrated in FIG. 14, the display unit with a touch detectionfunction 10 includes the pixel substrate 2, the counter substrate 3 thatis disposed so as to face a surface of the pixel substrate 2 in thevertical direction, and a liquid crystal layer 6 serving as a displayfunction layer that is interposed between the pixel substrate 2 and thecounter substrate 3.

The pixel substrate 2 includes a first substrate 21 serving as a circuitboard, pixel electrodes 22, second detection electrodes 23, driveelectrodes COML, and an insulating layer 24. The first substrate 21 isprovided with thin film transistors (TFT) serving as switching elementsin a manner corresponding to the pixel electrodes 22. The pixelelectrodes 22 are provided in a matrix above the first substrate 21 inplanar view. The second detection electrodes 23 detect pressure. Thedrive electrodes COML are provided between the first substrate 21 andthe pixel electrodes 22. The insulating layer 24 provides electricalinsulation between the pixel electrodes 22 and the drive electrodesCOML. A polarizing plate 65B may be provided below the first substrate21 with an adhesive layer 66B interposed therebetween.

The first substrate 21 is provided with a display control integratedcircuit (IC) 19. The display control IC 19 is a chip that ischip-on-glass (COG) mounted on the first substrate 21, and incorporatesthe controller 11 described above. A flexible substrate 72 is coupled toan end of the first substrate 21. The display control IC 19 outputs thecontrol signals to, for example, scan signal lines GCL and pixel signallines SGL (to be described later) based on the video signal Vdisp (referto FIG. 1) supplied from an external host IC (not illustrated).

The counter substrate 3 includes a second substrate 31 and a colorfilter 32 provided on one surface of the second substrate 31. The othersurface of the second substrate 31 is provided with the first detectionelectrodes TDL serving as detection electrodes of the touch panel 30. Aprotective layer 39 is provided on the first detection electrodes TDL.Furthermore, a polarizing plate 65A is provided above the firstdetection electrodes TDL with an adhesive layer 66A interposedtherebetween. A flexible substrate 71 is coupled to the second substrate31. The flexible substrate 71 is coupled to the first detectionelectrodes TDL through frame wire 37 described later. The color filter32 may be disposed on the first substrate 21. The first substrate 21 andthe second substrate 31 are, for example, glass substrates.

The first substrate 21 and the second substrate 31 are arranged so as toface each other with a spacer 61 providing a predetermined gaptherebetween. The liquid crystal layer 6 is provided in a space betweenthe first substrate 21 and the second substrate 31. The liquid crystallayer 6 modulates light passing therethrough according to the state ofan electric field, and is made of, for example, liquid crystals of ahorizontal electric field mode, such as an in-plane switching (IPS)mode, including a fringe field switching (FFS) mode. Orientation filmsmay be provided between the liquid crystal layer 6 and the pixelsubstrate 2 and between the liquid crystal layer 6 and the countersubstrate 3 illustrated in FIG. 14.

As illustrated in FIG. 15, the display device with a touch detectionfunction 1 has a display area 10 a and a frame area 10 b. The displayarea 10 a is an area for displaying an image, and the frame area 10 b ispositioned on the outer side of the display area 10 a. The display area10 a has a rectangular shape having two long sides and short sidesfacing each other. The frame area 10 b has a frame shape surrounding thefour sides of the display area 10 a. The display area 10 a according tothe present embodiment is an area for displaying an image. In a casewhere an image is displayed by the liquid crystal layer 6 or a whiteorganic light-emitting diode (OLED) layer, for example, the display area10 a corresponds to a transmissive area on the color filter 32. In thecase of a reflective display device, the display area 10 a correspondsto a reflective area on which incident light is reflected. In a casewhere an image is displayed by a colored OLED, for example, the displayarea 10 a corresponds to an area including light-emitting elements thatcan develop colors.

The drive electrodes COML are provided in the display area 10 a of thefirst substrate 21. The drive electrodes COML extend in a directionalong the long sides of the display area 10 a, and are arranged in adirection along the short sides of the display area 10 a. Alight-transmitting electrically conductive material, such as indium tinoxide (ITO), is used for the drive electrodes COML.

The second detection electrodes 23 are arrayed in directions along thelong side and the short side of the display area 10 a. The seconddetection electrodes 23 arrayed in the direction along the long side ofthe display area 10 a are referred to as second detection electrodes23A, whereas the second detection electrodes 23 arrayed in the directionalong the short side of the display area 10 a are referred to as seconddetection electrodes 23B. The second detection electrodes 23A and 23Bare arranged in a manner surrounding the display area 10 a. The seconddetection electrodes 23A and 23B simply need to surround at least twosides of the display area 10 a. The second detection electrodes 23A and23B each have a rectangular shape. A plurality of second detectionelectrodes 23A are arrayed along one drive electrode COML. The length ofthe long side of the second detection electrode 23A is shorter than thelength of the drive electrode COML in the extending direction.

The drive electrode driver 14 and the display control IC 19 are disposedon a short-side side of the frame area 10 b of the first substrate 21,and the gate driver 12 is disposed on long-side sides of the frame area10 b. The flexible substrate 72 is coupled to the short-side side of theframe area 10 b. The drive electrode driver 14 and the flexiblesubstrate 72 are arranged near an end in the extending direction of thedrive electrodes COML. This arrangement can reduce the length of wiringlines from the drive electrodes COML, and reduce the area of the framearea 10 b.

As illustrated in FIG. 16, the first detection electrodes TDL areprovided in the display area 10 a of the second substrate 31. The firstdetection electrodes TDL extend in the direction along the short side ofthe display area 10 a and are arrayed in the direction along the longside of the display area 10 a. The first detection electrodes TDL eachinclude a plurality of metal wires 33 a and 33 b. The metal wires 33 aand 33 b each have a plurality of bends and are formed into zigzag linesor wavy lines. The metal wires 33 a and 33 b extend in the directionalong the short side of the display area 10 a. The metal wires 33 a and33 b are alternately arrayed in the direction along the long side of thedisplay area 10 a. The bends of the metal wire 33 a and the bends of themetal wire 33 b according to the present embodiment are coupled to eachother, whereby the first detection electrodes TDL serve as mesh-likemetal wiring. The metal wires 33 a and 33 b are separated by slits SL.The slits SL are formed at positions indicated by the dotted lines A inFIG. 16. The metal wires 33 a and 33 b separated by the slits SLfunction as one first detection electrode TDL.

Conductive layers 35 according to the present embodiment are provided onthe short sides of the frame area 10 b apart from the first detectionelectrodes TDL. The conductive layers 35 each include a plurality ofmetal wires 33 a and 33 b and have a mesh shape. The conductive layers35 are provided at positions superimposed on the second detectionelectrodes 23B illustrated in FIG. 15. By supplying, to the conductivelayers 35, guard signals Vsg1 synchronized with and having the samewaveform as that of the second drive signals Vd supplied to the seconddetection electrodes 23B, stray capacitance generated in the seconddetection electrodes 23B can be reduced. The ends of the first detectionelectrodes TDL are provided in a manner superimposed on the seconddetection electrodes 23A. By supplying the guard signals Vsg1 also tothe second detection electrodes 23A, stray capacitance generated in thesecond detection electrodes 23A can be reduced.

The metal wires 33 a and 33 b are made of a metal material including atleast one of aluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo),and an alloy of these metals. The metal wires 33 a and 33 b may be alaminated body having a plurality of layers made of one or more of thesemetal materials. A metal material including at least one of Al, Cu, Ag,and an alloy of these metals has lower resistance than that of atranslucent conductive oxide, such as ITO, as a material for atranslucent electrode. The metal material including at least one of Al,Cu, Ag, and an alloy of these metals has a light shielding propertycompared with a translucent conductive oxide, such as ITO. With thisproperty, the metal material may possibly have lower transmittance, orthe patterns of the first detection electrodes TDL are likely to bevisually recognized. To address this, each first detection electrode TDLaccording to the present embodiment includes a plurality of thin metalwires 33 a and 33 b, and the metal wires 33 a and 33 b are arranged in amesh shape by interposing a gap larger than the width of the metal wiretherebetween. With this structure, the first detection electrodes TDLcan have lower resistance and be made invisible. As a result, the firstdetection electrodes TDL have lower resistance, and the display devicewith a touch detection function 1 can have a smaller width, a largerscreen, or higher definition.

The width of the metal wires 33 a and 33 b preferably falls within arange of 2 μm to 10 μm. If the width of the metal wires 33 a and 33 b isset to 10 μm or smaller, the area covering apertures is reduced in thedisplay area 10 a, and thus the aperture ratio is less likely to bereduced. The apertures correspond to areas in which transmission oflight is not suppressed by a black matrix or the scan signal lines GCLand the pixel signal lines SGL. If the width of the metal wires 33 a and33 b is set to 2 μm or larger, the shape of the metal wires 33 a and 33b is stabilized, and thus breaking of the wire is less likely to occur.To reduce the reflectance, the outermost surface of the metal wires 33 aand 33 b is preferably subjected to blackening.

As illustrated in FIG. 16, a plurality of frame wires 37 extending fromthe first detection electrodes TDL are provided in the frame area 10 bof the second substrate 31. The flexible substrate 71 is coupled on theshort side of the frame area 10 b of the second substrate 31. The framewires 37 extend along the long sides of the frame area 10 b and arecoupled to the flexible substrate 71. The flexible substrate 71 isprovided with a touch detection IC 18. The touch detection IC 18includes the detector 40 illustrated in FIG. 1. The first detectionsignals Vdet1 output from the first detection electrodes TDL aresupplied to the touch detection IC 18 via the frame wires 37 and theflexible substrate 71.

In the present embodiment, the detector 40 is a touch driver IC that ismounted on the flexible substrate 71. However, some of the functions ofthe detector 40 may be provided as a function of another microprocessingunit (MPU).

Specifically, a circuit, such as the MPU, provided separately from thetouch driver IC may perform some functions (such as denoising) amongvarious functions, such as the A/D conversion and the denoising that canbe provided as functions of the touch driver IC.

The flexible substrate 71 is coupled to the flexible substrate 72 via aconnector 72 a. With this configuration, the second drive signals Vd aresupplied to the second detection electrodes 23 from the second detectionelectrode driver 48 (refer to FIG. 1) mounted on the touch detection IC18. The second detection signals Vdet2 output from the second detectionelectrodes 23 are supplied to the touch detection IC 18.

The following describes a display operation of the display panel 20.FIG. 17 is a circuit diagram illustrating a pixel array of the displayunit with a touch detection function according to the first embodiment.As illustrated in FIG. 17, thin film transistor elements (hereinafter,called TFT elements) Tr of the sub-pixels SPix, and wires, such as thepixel signal lines SGL and the scan signal lines GCL, are formed on thefirst substrate 21 (refer to FIG. 14). The pixel signal lines SGL supplythe pixel signals Vpix to each of the pixel electrodes 22 and the scansignal lines GCL supply the drive signals for driving the TFT elementsTr. The pixel signal lines SGL and the scan signal lines GCL extend in aplane parallel to a surface of the first substrate 21.

The display panel 20 illustrated in FIG. 17 includes the sub-pixels SPixarranged in a matrix. Each of the sub-pixels SPix includes correspondingone of the TFT elements Tr and a liquid crystal element LC. The TFTelement Tr is constituted by a thin-film transistor, and in the presentexample, constituted by an n-channel metal oxide semiconductor (MOS)TFT. The source of the TFT element Tr is coupled to one of the pixelsignal lines SGL; the gate thereof is coupled to one of the scan signallines GCL; and the drain thereof is coupled to one end of the liquidcrystal element LC. One end of the liquid crystal element LC is coupledto the drain of the TFT element Tr, and the other end thereof is coupledto the drive electrode COML.

The sub-pixel SPix is mutually coupled through the scan signal line GCLwith another sub-pixel SPix belonging to the same row of the displaypanel 20. The scan signal line GCL is coupled to the gate driver 12(refer to FIG. 1), and is supplied with the scan signal Vscan from thegate driver 12. The sub-pixel SPix is mutually coupled through the pixelsignal line SGL with another sub-pixel SPix belonging to the same columnof the display panel 20. The pixel signal line SGL is coupled to thesource driver 13 (refer to FIG. 1), and is supplied with the pixelsignal Vpix from the source driver 13. The sub-pixel SPix is furthermutually coupled through the drive electrode COML with another sub-pixelSPix belonging to the same column. The drive electrode COML is coupledto the drive electrode driver 14 (refer to FIG. 1), and is supplied withthe first drive signal Vcom from the drive electrode driver 14. Thismeans that the sub-pixels SPix belonging to the same one of the columnsshare one of the drive electrodes COML. In the present embodiment, thedirection of extension of the drive electrodes COML is parallel to thatof the pixel signal lines SGL.

The gate driver 12 illustrated in FIG. 1 drives so as to sequentiallyscan the scan signal lines GCL. The gate driver 12 applies the scansignal Vscan (refer to FIG. 1) to the gates of the TFT elements Tr ofthe sub-pixels SPix through the scan signal lines GCL so as tosequentially select, as a target of display driving, one row (onehorizontal line) of the sub-pixels SPix. The source driver 13 suppliesthe pixel signals Vpix through the pixel signal lines SGL to thesub-pixels SPix constituting the selected one horizontal line. Thesub-pixels SPix are configured to display one horizontal line at a timeaccording to the supplied pixel signals Vpix. While the displayoperation is performed, the drive electrode driver 14 apples the firstdrive signals Vcom to the drive electrodes COML. The pixel electrodes 22are supplied with a common potential by each of the first drive signalsVcom for the display operation.

The color filter 32 illustrated in FIG. 14 may include periodicallyarranged color regions colored in, for example, three colors of red (R),green (G), and blue (B). Color regions 32R, 32G, and 32B of the threecolors of R, G, and B are associated, as one set, with the sub-pixelsSPix illustrated in FIG. 17, and the sub-pixels SPix corresponding tothe color regions 32R, 32G, and 32B of the three colors constitute apixel Pix as a one set. As illustrated in FIG. 14, the color filter 32faces the liquid crystal layer 6 in a direction orthogonal to the firstsubstrate 21. The color filter 32 may have a combination of other colorsas long as being colored in different colors from each other. The colorfilter 32 is not limited to having a combination of three colors, butmay have a combination of four or more colors.

As illustrated in FIG. 17, in the present embodiment, the driveelectrodes COML extend in the direction parallel to the extendingdirection of the pixel signal lines SGL, and extend in the directionintersecting the extending direction of the scan signal lines GCL. Thisarrangement allows the wire from the drive electrodes COML to be ledtoward the short-side side of the frame area 10 b (toward the flexiblesubstrate 72) (refer to FIG. 15). As a result, compared with a case ofproviding the drive electrodes COML in the direction orthogonal to thepixel signal lines SGL, the drive electrode driver 14 need not beprovided on a long-side side of the frame area 10 b, so that the framearea 10 b can have a smaller width. The drive electrodes COML are notlimited to extending in this direction, but may extend, for example, inthe direction parallel to the scan signal lines GCL.

The drive electrodes COML illustrated in FIGS. 14 and 15 serve as commonelectrodes each supplying the common potential to the pixel electrodes22 of the display panel 20, and also serve as drive electrodes when thetouch detection using the mutual capacitance method is performed on thetouchscreen 30. The drive electrodes COML may serve as detectionelectrodes when the touch detection using the self-capacitance method isperformed on the touch panel 30. FIG. 18 is a perspective viewillustrating a configuration example of the drive electrodes and thefirst detection electrodes of the display unit with a touch detectionfunction according to the first embodiment. The touch panel 30 isconstituted by the drive electrodes COML provided on the pixel substrate2 and the first detection electrodes TDL provided on the countersubstrate 3.

The drive electrodes COML include a plurality of stripe-shaped electrodepatterns extending in the right-left direction of FIG. 18. The firstdetection electrodes TDL include a plurality of electrode patternsextending in a direction intersecting the extending direction of theelectrode patterns of the drive electrodes COML. The first detectionelectrodes TDL face the drive electrodes COML in the directionorthogonal to the surface of the first substrate 21 (refer to FIG. 14).Each of the electrode patterns of the first detection electrodes TDL iscoupled to the input to the detection signal amplifier 42 of thedetector 40 (refer to FIG. 1). An electrostatic capacitance is formed atan intersecting portion between each of the electrode patterns of thedrive electrodes COML and that of the first detection electrodes TDL.

The first detection electrodes TDL and the drive electrodes COML (driveelectrode blocks) are not limited to having the divided stripe shapes.The first detection electrodes TDL and the drive electrodes COML mayhave, for example, comb-tooth shapes. Otherwise, the first detectionelectrodes TDL and the drive electrodes COML only need to be dividedinto a plurality of portions. The shape of the slits dividing the driveelectrodes COML may be linear or curved.

When the touch panel 30 performs the touch detection operation using themutual capacitance method, this configuration causes the drive electrodedriver 14 to drive the drive electrodes so as to sequentially scan thedrive electrode blocks in a time-division manner, so that each detectionblock of the drive electrodes COML is sequentially selected along a scandirection Ds. The first detection signal Vdet1 is output from the firstdetection electrode TDL, so that the touch detection of one detectionblock is performed. That is, each of the drive electrode blockscorresponds to the drive electrode E1 in the basic principle of themutual capacitance touch detection described above, and the firstdetection electrode TDL corresponds to the detection electrode E2. Thetouch panel 30 is configured to detect the touch input according to thisbasic principle. As illustrated in FIG. 18, in the touch panel 30, thefirst detection electrodes TDL and the drive electrodes COMLintersecting each other constitute a capacitance touch sensor in amatrix form. Consequently, by scanning the entire touch detectionsurface of the touch panel 30, the touch panel 30 can detect a positionwhere the conductor externally comes in contact therewith or inproximity thereto.

FIG. 19 is an explanatory diagram for explaining pressure detectionperformed by the display device with a touch detection functionaccording to the first embodiment. As described above, the conductor 104(e.g., the housing 103 or the display device housing 107) is providedapart from the first substrate 21 and facing the second detectionelectrode 23. A capacitor C6 is generated between the second detectionelectrode 23 and the conductor 104. When pressure is applied to theinput surface 101 a of the cover member 101 (refer to FIGS. 11 to 13),the cover member 101 is deformed so as to slightly bend toward theconductor 104 depending on the pressure. The first substrate 21 of thedisplay device with a touch detection function 1 is bent together withthe cover member 101, which reduces the gap between the second detectionelectrode 23 and the conductor 104, thereby increasing the capacitor C6.

Based on the detection principle of the self-capacitance method, thesecond detection signal Vdet2 is output from the second detectionelectrode 23. In other words, the second detection electrode 23corresponds to the detection electrode E2 in the detection principle ofthe self-capacitance method. The magnitude of pressure applied to theinput surface 101 a can be detected based on the second detectionsignals Vdet2 output from the respective second detection electrodes 23.When an object is in contact with the input surface 101 a, the seconddetection electrodes 23 can detect the magnitude of the pressure or theone-dimensional coordinates of the pressure. Because the seconddetection electrodes 23A and 23B are arrayed as individual electrodes,they can detect distribution of the pressure applied to the inputsurface 101 a. The present embodiment includes the second detectionelectrodes 23 besides the first detection electrodes TDL. With thisconfiguration, the present embodiment can detect the position at whichan external conductor is in contact with or in proximity to the inputsurface 101 a and the magnitude of the pressure applied at the detectedposition. The display device with a touch detection function 1 cancombine the detection results and reflect them on various applications.

The following describes the configuration of the second detectionelectrodes 23 in detail. FIG. 20 is a schematic plan view illustratingthe drive electrodes and the second detection electrodes according tothe first embodiment in an enlarged manner. FIG. 21 is a sectional viewalong line XXI-XXI′ in FIG. 20. As illustrated in FIG. 20, the seconddetection electrodes 23A are provided in the frame area 10 b along thelong side of the display area 10 a. The second detection electrodes 23Bare provided in the frame area 10 b along the short side of the displayarea 10 a. The second detection electrodes 23A and 23B are coupled tocoupling wires 38 through respective contact holes H1. The shape and thenumber of the second detection electrodes 23A and 23B are given by wayof example only and may be appropriately changed. While the seconddetection electrodes 23B are arranged in a manner corresponding to therespective drive electrodes COML, the arrangement of the seconddetection electrodes 23B is not limited thereto. The number of thesecond detection electrodes 23B may be larger than or smaller than thatof the drive electrodes COML. In the present specification, the “framearea 10 b” indicates an area positioned on the inner side of the outerperiphery of the first substrate 21 and on the outer side of the displayarea 10 a.

The drive electrode driver 14 includes a drive electrode scanning unit14 a and a first drive signal generating unit 14 b. The first drivesignal generating unit 14 b generates the first drive signals Vcom andsupplies them to the drive electrode scanning unit 14 a. To perform themutual capacitance touch detection described above, the drive electrodescanning unit 14 a performs scanning in a manner sequentially selectingone detection block of the drive electrodes COML. The drive electrodescanning unit 14 a supplies the first drive signals Vcom to the driveelectrodes COML of the selected one detection block.

The drive electrode scanning unit 14 a is coupled to the seconddetection electrodes 23A and 23B via the coupling wires 38. The driveelectrode scanning unit 14 a sequentially or simultaneously selects thesecond detection electrodes 23A and 23B. A second drive signalgenerating unit 48 a included in the second detection electrode driver48 (refer to FIG. 1) generates the second drive signals Vd and suppliesthem to the drive electrode scanning unit 14 a. The second drive signalgenerating unit 48 a may be mounted on the touch detection IC 18 (referto FIG. 16). To detect pressure, the drive electrode scanning unit 14 aselects the second detection electrodes 23A and 23B as detection targetsand supplies the second drive signals Vd to the selected seconddetection electrodes 23A and 23B. The second detection electrodes 23Aand 23B output, to the detector 40, output signals depending oncapacitance change between the conductor 104 and the second detectionelectrodes 23A and 23B. The drive electrode scanning unit 14 a iscoupled to the drive electrodes COML and the second detection electrodes23A and 23B. Alternatively, a scanning unit that scans the driveelectrodes COML and a scanning unit that scans the second detectionelectrodes 23A and 23B may be separately provided.

The second detection electrodes 23A and 23B according to the presentembodiment are provided around the display area 10 a, and they eachdetect pressure. With this configuration, the present embodiment canaccurately detect the pressure. In pressure detection using the driveelectrodes COML, for example, it may possibly be difficult to detectpressure distribution in the extending direction of the drive electrodesCOML due to no resolution for information on pressure in the extendingdirection of the drive electrodes COML. The second detection electrodes23A according to the present embodiment are provided along at least oneside of the display area 10 a and arrayed in the extending direction ofthe drive electrodes COML. With this configuration, the presentembodiment can accurately detect pressure distribution in a directionalong the extending direction of the drive electrodes COML.

In other words, the present embodiment can detect the coordinates ofpressure in different directions by the second detection electrodes 23Aand 23B provided along the periphery of the display area 10 a and by thedrive electrodes COML. Based on the results, the present embodiment cancalculate the two-dimensional coordinates of the applied pressure. Thepresent embodiment can calculate pressure applied at a plurality ofpoints using the longitudinal and lateral pressure sensors (the seconddetection electrodes 23A and 23B). Furthermore, the present embodimentcan readily complement pressure sensor information using information onthe coordinates and the number of fingers, for example, detected on thecapacitance touch panel 30. The pressure sensors in the frame area 10 bare arranged left and right, top and bottom. By comparing the pressurevalue detected by the pressure sensors arranged left and right (seconddetection electrodes 23A) with the coordinates of a finger, the presentembodiment can calculate the pressure value at the position pressed bythe finger. If output of the pressure value varies in the plane, thepresent embodiment creates a correction table in advance. By comparingthe output with the correction table, the present embodiment can readilycorrect the variation of the pressure value.

The second detection electrodes 23A and 23B simply need to be providedalong at least two sides of the display area 10 a. This configurationrequires a smaller number of detection electrodes than a case where aplurality of electrodes are arranged in a matrix within the display area10 a. As a result, the configurations of the touch detection IC 18 andthe second detection electrode driver 48 can be simplified. Even when aninput operation is performed at a plurality of positions, the inputpositions are detected by the drive electrodes COML and the firstdetection electrodes TDL. Based on the information on the inputpositions and the information on pressure, the present embodiment cantherefore calculate the pressure applied at the input positions.

While the second detection electrodes 23A and 23B according to thepresent embodiment are provided in the frame area 10 b, the arrangementof the second detection electrodes 23A and 23B is not limited thereto.The second detection electrodes 23A and 23B may be provided in thedisplay area 10 a or across the display area 10 a and the frame area 10b.

As illustrated in FIG. 21, the first substrate 21 has a first surface 21a and a second surface 21 b opposite to the first surface 21 a. The scansignal lines GCL is provided on the first surface 21 a side with aninsulating layer 58 a and an insulating layer 58 b interposedtherebetween. The coupling wire 38 is provided on the insulating layer58 b at the same layer as that of the scan signal lines GCL. Aninsulating layer 58 c is provided on the coupling wire 38 and the scansignal lines GCL, and the pixel signal lines SGL are provided on theinsulating layer 58 c. A planarization layer 58 d is provided on thepixel signal lines SGL, and the drive electrodes COML are provided onthe planarization layer 58 d. A plurality of conductive wires 51 areprovided on the drive electrodes COML. The insulating layer 24 isprovided on the drive electrodes COML and the conductive wire 51. Thepixel electrodes 22 and the second detection electrodes 23 are providedon the insulating layer 24. The conductor 104 is arranged on the secondsurface 21 b side of the first substrate 21 apart from the firstsubstrate 21.

The conductive wires 51 are provided on the drive electrodes COML atpositions superimposed on the pixel signal lines SGL. The conductivewire 51 is made of the same metal material as that of the metal wires 33a and 33 b of the first detection electrodes TDL. The conductive wire 51is made of a metal material including at least one of Al, Cu, Ag, Mo,and an alloy of these metals. With the conductive wire 51, the apparentresistance of the drive electrodes COML (total resistance of the driveelectrodes COML and the conductive wire 51) is reduced compared with acase where the drive electrodes COML alone are provided.

The second detection electrodes 23 according to the present embodimentare provided at the same layer as that of the pixel electrodes 22. Thesecond detection electrodes 23 are provided in the layer closer to thesecond substrate 31 than the drive electrodes COML. In this case, thesecond detection electrodes 23 are preferably provided at positions notsuperimposed on the drive electrodes COML. With this configuration, thepresent embodiment can accurately detect capacitance change between thesecond detection electrodes 23 and the conductor 104. The seconddetection electrodes 23 can be made of the same material as that of thepixel electrodes 22 and made of a translucent conductive material, suchas ITO.

As illustrated in FIG. 21, the display area 10 a of the second substrate31 is provided with the color regions 32R, 32G, and 32B of the colorfilter 32, and the frame area 10 b is provided with a light shieldinglayer 36. The first detection electrodes TDL on the upper surface of thesecond substrate 31 preferably extend to the positions superimposed onthe second detection electrodes 23. By supplying, to the first detectionelectrodes TDL, the guard signals Vsg1 synchronized with and having thesame waveform as that of the second drive signals Vd in pressuredetection, the first detection electrodes TDL serve as guard electrodes.This mechanism can reduce stray capacitance in the second detectionelectrodes 23. As a result, the present embodiment can output the seconddrive signals Vd supplied to the second detection electrodes 23 in aresponsive waveform, thereby suppressing reduction in the detectionsensitivity. Because variation in the stray capacitance is reduced, thepresent embodiment can suppress an error in the second detection signalsVdet2, thereby suppressing reduction in the detection accuracy. Theguard signals Vsg1 may be supplied from the second drive signalgenerating unit 48 a or another power source.

The following describes a driving method of the display device with atouch detection function 1 according to the present embodiment. FIG. 22is a timing waveform diagram of an exemplary operation performed by thedisplay device with a touch detection function according to the firstembodiment.

In an example of an operating method of the display device with a touchdetection function 1, the display device with a touch detection function1 performs a touch detection operation (touch detection period), apressure detection operation (pressure detection period), and a displayoperation (display operation period) in a time division manner. Thetouch detection operation, the pressure detection operation, and thedisplay operation may be performed in any division manner. The followingdescribes a case where the touch detection operation, the pressuredetection operation, and the display operation are performed in a mannereach divided into a plurality of parts in one frame period (1F) of thedisplay panel 20, that is, a time required to display video informationof one screen.

As illustrated in FIG. 22, when a control signal (TS-VD) is turned on(high level), one frame period (1F) is started. A control signal (TS-HD)is repeatedly turned on (high level) and off (low level) in one frameperiod (1F). In the period when the control signal (TS-HD) is turned on,the touch detection operation or the pressure detection operation isperformed. In the period when the control signal (TS-HD) is turned off,the display operation is performed. The control signal (TS-VD) and thecontrol signal (TS-HD) are output based on clock signals generated by aclock generating unit of the controller 11 (refer to FIG. 1). One frameperiod (1F) is composed of a plurality of display operation periodsPd_(x) (x=1, 2, . . . n), a plurality of touch detection periods Pt_(x)(x=1, 2, . . . m) for performing the touch detection operation, and aplurality of pressure detection periods Pf₁, Pf₂, and Pf₃ for performingthe pressure detection operation. These periods are alternately arrangedon a temporal axis as follows: the pressure detection period Pf₁, thedisplay operation period Pd₁, the touch detection period Pt₁, thedisplay operation period Pd₂, the touch detection period Pt₂, etc.

The controller 11 supplies the pixel signals Vpix to the pixels Pix(refer to FIG. 17) in a plurality of rows selected in each displayoperation period Pd_(x) via the gate driver 12 and the source driver 13.FIG. 22 illustrates a selection signal (SELR/G/B) for selecting threecolors of RGB and a video signal (SIGn) for each color. Based on theselection signal (SELR/G/B), sub-pixels SPix corresponding thereto areselected. Subsequently, the video signal (SIGn) for each color issupplied to the selected sub-pixels SPix, whereby an operation fordisplaying an image is performed. In each display operation periodPd_(x), an image obtained by dividing the video signals Vdisp of onescreen into n is displayed. Through the display operation periods Pd₁,Pd₂, . . . Pd_(n), video information of one screen is displayed. Thedrive electrodes COML also serve as the common electrodes of the displaypanel 20. In the display operation period Pd_(x), the drive electrodedriver 14 supplies, to the selected drive electrodes COML, the firstdrive signals Vcom serving as a common potential for display drive.

In the touch detection periods Pt_(x) (x=1, 2, . . . m), the controller11 outputs control signals to the drive electrode driver 14. The driveelectrode driver 14 supplies the first drive signals Vcom for touchdetection to the drive electrodes COML. Based on the basic principle ofthe mutual capacitance touch detection described above, the detector 40determines whether touch input is performed on the display area 10 a andcalculates the coordinates of the input position by the first detectionsignals Vdet1 supplied from the first detection electrodes TDL.

In the touch detection period Pt_(x), the scan signal lines GCL and thepixel signal lines SGL (refer to FIG. 17) may be in a floating statewhere no voltage signal is supplied thereto and their electric potentialis not fixed. The scan signal lines GCL and the pixel signal lines SGLmay be supplied with a signal synchronized with and having the samewaveform as that of the first drive signal Vcom. This mechanismsuppresses capacitive coupling between the drive electrodes COML and thescan signal lines GCL and capacitive coupling between the driveelectrodes COML and the pixel signal lines SGL, thereby reducing straycapacitance. The present embodiment thus can suppress reduction of thedetection sensitivity in touch detection.

In the pressure detection periods Pf₁, Pf₂, and Pf₃, the controller 11outputs control signals to the second detection electrode driver 48. Thesecond detection electrode driver 48 supplies the second drive signalsVd to the second detection electrodes 23. Based on the basic principleof the self-capacitance method described above, the detector 40calculates pressure applied to the input surface 101 a (refer to FIG. 11and other figures) by the second detection signals Vdet2 supplied fromthe second detection electrodes 23. In the pressure detection periodsPf₁, Pf₂, and Pf₃, the second detection electrode driver 48 supplies theguard signals Vsg1 to the first detection electrodes TDL. While theguard signal Vsg1 preferably has a waveform with the same amplitude andthe same frequency as those of the second drive signal Vd, it may have adifferent amplitude.

The pressure detection periods Pf₁, Pf₂, and Pf₃ are arranged at periodsdifferent from the touch detection periods Pt_(x) (x=1, 2, . . . m).With this setting, the first detection electrodes TDL can be used asguard electrodes in the pressure detection periods Pf₁, Pf₂, and Pf₃.The present embodiment thus can suppress generation of stray capacitanceand accurately detect pressure. The guard electrode in this caseindicates an electrode facing the position where stray capacitance isgenerated and the electrode to which the same waveform as that of thedrive waveform in pressure detection is applied so as to reduce thestray capacitance.

The present embodiment may perform detection using all the seconddetection electrodes 23 in every period of the pressure detectionperiods Pf₁, Pf₂, and Pf₃. Alternatively, the present embodiment mayperform detection while dividing the second detection electrodes 23 foreach period. While the pressure detection periods Pf₁, Pf₂, and Pf₃ areprovided as three periods in one frame period (1F), the pressuredetection period may be provided at least as one period or four or moreperiods. The arrangement of the pressure detection periods Pf₁, Pf₂, andPf₃ in one frame period (1F) can be changed. The pressure detectionperiods Pf₁, Pf₂, and Pf₃ may be arranged after all the touch detectionperiods Pt_(x), for example.

As described above, the display device with a touch detection function 1according to the present embodiment includes the first substrate 21, thedrive electrodes COML (first electrodes), the second detectionelectrodes 23 (second electrodes), and the conductor 104. The firstsubstrate 21 has the first surface 21 a and the second surface 21 bopposite to the first surface 21 a. The drive electrodes COML areprovided in the display area 10 a of the first substrate 21 and detectan external proximate object that is in contact with or in proximity tothe first surface 21 a side of the first substrate 21. The seconddetection electrodes 23 are provided along at least one side of thedisplay area 10 a. The conductor 104 is provided on the second surface21 b side of the first substrate 21 apart from the first substrate 21and forms an electrostatic capacitor between the conductor 104 and thesecond detection electrodes 23.

The present embodiment can both detect the position where the externalproximate object is in contact with or in proximity to the first surface21 a side and detect the magnitude of pressure applied to the detectedposition. Because the second detection electrodes 23 are provided alongat least one side of the display area 10 a, the present embodiment canaccurately detect pressure distribution. With the second detectionelectrodes 23A and 23B provided along the display area 10 a and with thedrive electrodes COML, the present embodiment can calculate the pressurevalue at the position to which the pressure is applied.

Second Embodiment

FIG. 23 is a schematic sectional view schematically illustrating asectional structure of the display device with a touch detectionfunction according to a second embodiment. The second detectionelectrodes 23 according to the present embodiment are provided on thefirst surface 21 a side of the first substrate 21 with the insulatinglayer 58 a interposed therebetween. The second detection electrodes 23are arranged at a layer different from those of the pixel electrodes 22,the drive electrodes COML, the pixel signal lines SGL, and the scansignal lines GCL. The second detection electrodes 23 are arranged at alayer closer to the first substrate 21 than the scan signal lines GCL.The coupling wires 38 are provided at the same layer as that of the scansignal lines GCL and coupled to the second detection electrodes 23through respective contact holes H2. The arrangement of the seconddetection electrodes 23, the coupling wires 38, and other components inplanar view is the same as the arrangement illustrated in FIG. 20.

With this configuration, the second detection electrodes 23 are providedcloser to the first substrate 21 than the various wires and electrodes,thereby reducing the distance between the conductor 104 and the seconddetection electrodes 23. The present embodiment thus can improve thesensitivity in pressure detection. This configuration requires a smallernumber of conductors, such as wires, arranged between the seconddetection electrodes 23 and the conductor 104. The present embodimentthus can reduce generation of stray capacitance between various wiresand the second detection electrodes 23, thereby improving the accuracyin pressure detection.

Third Embodiment

FIG. 24 is a schematic plan view illustrating the drive electrodes andthe second detection electrodes according to a third embodiment in anenlarged manner. FIG. 25 is a sectional view along line XXV-XXV′ in FIG.24.

As illustrated in FIG. 24, the second detection electrodes 23 accordingto the present embodiment are provided in the display area 10 a. Thesecond detection electrodes 23A are arranged along the long side of thedisplay area 10 a in a manner superimposed on the drive electrode COML.The second detection electrodes 23B are arranged along the short side ofthe display area 10 a in a manner superimposed on the ends of the driveelectrodes COML in the extending direction.

FIG. 24 illustrates the first detection electrode TDL by the alternatelong and two short dashes line. To simplify the drawing, FIG. 24schematically illustrates one first detection electrode TDL. The firstdetection electrode TDL extends in a direction intersecting with theextending direction of the drive electrodes COML. The first detectionelectrode TDL has a first portion TDLa and a second portion TDLb. Thesecond portion TDLb corresponds to the end of the first detectionelectrode TDL in the extending direction. The first portion TDLacorresponds to a portion positioned at the center of the display area 10a. The second portion TDLb is an area having lower detection sensitivityin touch detection, and the second detection electrode 23 is arranged atan area under the second portion TDLb. The configuration of the firstportion TDLa and the second portion TDLb of the first detectionelectrode TDL will be described later in detail.

As illustrated in FIG. 25, the second detection electrodes 23 areprovided on the insulating layer 58 a above the first substrate 21. Theinsulating layer 58 b is provided on the second detection electrodes 23,and the scan signal lines GCL are provided on the insulating layer 58 b.The insulating layer 58 c is provided on the scan signal lines GCL, andthe pixel signal lines SGL are provided on the insulating layer 58 c.The planarization layer 58 d is provided on the pixel signal lines SGL,and the drive electrodes COML are provided on the planarization layer 58d. The conductive wires 51 are provided on the drive electrodes COML.The insulating layer 24 is provided on the drive electrodes COML and theconductive wires 51. The pixel electrodes 22 are provided on theinsulating layer 24.

Part of the pixel signal lines SGL according to the present embodimentare coupled to the second detection electrodes 23 through respectivecontact holes H3. In other words, the pixel signal lines SGL also serveas the coupling wires 38, and the second detection electrodes 23 arecoupled to the drive electrode scanning unit 14 a via the coupling wires38 (pixel signal lines SGL) as illustrated in FIG. 24. As describedabove, the pressure detection periods Pf₁, Pf₂, and Pf₃ are arranged atperiods different from the display operation periods Pd_(x) (x=1, 2, . .. n). In the pressure detection periods Pf₁, Pf₂, and Pf₃, the TFTelements Tr (refer to FIG. 17) coupled to the respective sub-pixels SPixare turned off. Thus, even if the second drive signals Vd are suppliedvia the pixel signal lines SGL, and the second detection signals Vdet2are output via the pixel signal lines SGL, the present embodiment cansuppress an effect on the display image.

As described above, the second detection electrodes 23 according to thepresent embodiment are provided in the display area 10 a. With thisconfiguration, the area of the frame area 10 b can be reduced. Thesecond detection electrodes 23 are arranged under the second portionsTDLb of the first detection electrodes TDL. With this configuration, thepresent embodiment can detect pressure while suppressing reduction inthe touch detection sensitivity. Because the pixel signal lines SGL alsoserve as the coupling wires 38, the present embodiment requires noadditional wires in the display area 10 a, thereby saving the area ofthe aperture region.

FIG. 26 is a plan view of the first detection electrodes of the displaydevice with a touch detection function according to the thirdembodiment. FIG. 27 is a perspective view for schematically explaining afringing electric field generated between the drive electrode and theframe wire.

The first detection electrodes TDL are separated by the slits SL formedin the metal wires 33 a and 33 b. The separated first detectionelectrodes TDL are arrayed in a second direction Dy. FIG. 26 illustratestwo first detection electrodes TDL out of the first detection electrodesTDL. The first detection electrodes TDL each include the metal wires 33a and 33 b. The metal wires 33 a and 33 b have a line symmetric shapewith respect to a line parallel to a first direction Dx and arealternately arrayed in the second direction Dy. The bends of the metalwires 33 a and 33 b arrayed in the second direction Dy are coupled toeach other, thereby forming into intersections TDX. The metal wire 33 ais electrically coupled to the metal wire 33 b at the intersections TDX.With this configuration, the metal wires 33 a and 33 b have surroundedareas mesh1 surrounded by thin wire pieces Ua and Ub, thereby providingmesh-like metal wiring in the display area 10 a.

Coupling portions 57 are provided at both ends of the first detectionelectrodes TDL and are coupled to the metal wires 33 a and 33 b. Thefirst detection electrodes TDL are coupled to the frame wire 37 via thecoupling portions 57 provided at the ends in the first direction Dxside.

The first detection electrodes TDL each have the first portions TDLa andthe second portions TDLb. The first portions TDLa extend in the firstdirection Dx and are arrayed in the second direction Dy. Dummyelectrodes TDD are arranged between the first portions TDLa. The secondportions TDLb are arranged on both ends of the first detectionelectrodes TDL and extend in the first direction Dx. The second portionsTDLb are arranged along the boundary between the display area 10 a andthe frame area 10 b. One or a plurality of first portions TDLa arearranged between the second portions TDLb arranged at both ends, and thefirst portions TDLa are coupled to the second portions TDLb. The firstportions TDLa mainly function as the detection electrode E2 in theprinciple of the mutual capacitance touch detection described above. Thearea overlapping with the first portions TDLa in the first direction Dxcorresponds to a valid detection area SA. The areas overlapping with thesecond portions TDLb correspond to a peripheral area SB having lowerdetection sensitivity than that of the valid detection area SA.

Slits SLd are formed at positions indicated by the dotted lines B of themetal wires 33 a and 33 b as illustrated in FIG. 26 so that the dummyelectrodes TDD are separated from the first detection electrodes TDL.The dummy electrodes TDD do not function as touch detection electrodes.The dummy electrodes TDD have a rectangular shape with their long sidesextending in a direction along the first direction Dx. The dummyelectrodes TDD are arrayed in the second direction Dy in each firstdetection electrode TDL. The second portions TDLb may include the dummyelectrodes TDD.

The dummy electrodes TDD each include metal wires composed of aplurality of thin wire pieces Ud1 and Ud2 and the plurality of thin wirepieces Ud1 and Ud2 are repeatedly coupled to each other in the firstdirection Dx. The metal wires are coupled to each other in the seconddirection Dy. The dummy electrodes TDD have a mesh shape havingsurrounded areas mesh2 surrounded by the thin wire pieces Ud1 and Ud2.The slits SLd are formed in the thin wire pieces Ud1 and Ud2. Theprovision of the dummy electrodes TDD can reduce an electrostaticcapacitor between the first detection electrodes TDL and the driveelectrodes COML (refer to FIG. 15). Because the light transmittance ofthe part provided with the dummy electrodes TDD is substantially equalto that of the part provided with the first portions TDLa and the secondportions TDLb, the first detection electrodes TDL can be made invisible.The slits SLd may be provided at the intersections of the thin wirepieces Ud1 and Ud2.

As illustrated in FIG. 26, the frame wire 37 is provided near thedisplay area 10 a and extends in the second direction Dy. With thisconfiguration, as illustrated in FIG. 27, a fringing electric field Efmay possibly be generated between the drive electrodes COML provided tothe first substrate 21 and the frame wire 37. When a conductor, such asa finger, is in contact with or in proximity to the frame wire 37, thefinger blocks the fringing electric field Ef, thereby changing theelectrostatic capacitor. If the change in the electrostatic capacitor isoutput to the detector 40 via the frame wire 37, erroneous detection maypossibly occur. While three frame wires 37 are arranged in parallel inFIG. 27, a larger number of frame wires 37 may be arranged depending onthe number of first detection electrodes TDL.

The second portions TDLb according to the present embodiment function asshields that block the fringing electric field Ef between the driveelectrodes COML and the frame wire 37. With this configuration, thepresent embodiment can reduce the fringing electric field Ef, therebysuppressing erroneous detection. The second portions TDLb function notonly as shields but also as touch detection electrodes that detect afinger or the like being in contact with or in proximity to the secondportions TDLb.

As illustrated in FIGS. 24 and 25, the second detection electrodes 23according to the present embodiment are provided under the secondportions TDLb of the first detection electrodes TDL. In other words, thesecond detection electrodes 23 are provided in the peripheral area SBpositioned on the outer side of the valid detection area SA. Even thoughthe second detection electrodes 23 are provided, this configuration cansuppress reduction in the area of the valid detection area SA. As aresult, the present embodiment can detect pressure while suppressingreduction in the touch detection sensitivity. By supplying the guardsignals Vsg1 to the second portions TDLb in pressure detection, thepresent embodiment suppresses capacitive coupling between the conductorprovided on the first detection electrodes TDL side and the seconddetection electrodes 23, thereby reducing stray capacitance.

Fourth Embodiment

FIG. 28 is a plan view schematically illustrating the first substrate ofthe display device with a touch detection function according to a fourthembodiment. FIG. 29 is a plan view schematically illustrating the secondsubstrate of the display device with a touch detection functionaccording to the fourth embodiment. FIG. 30 is a schematic plan viewillustrating the drive electrodes and the second detection electrodesaccording to the fourth embodiment in an enlarged manner.

As illustrated in FIG. 28, the drive electrodes COML according to thepresent embodiment extend in a direction along the short side of thedisplay area 10 a and arrayed in a direction along the long side of thedisplay area 10 a. In other words, the drive electrodes COML extend in adirection along the extending direction of the scan signal lines GCL(refer to FIG. 17) and arrayed in a direction along the extendingdirection of the pixel signal lines SGL (refer to FIG. 17).

The second detection electrodes 23 according to the present embodimentare also arrayed in directions along the long side and the short side ofthe display area 10 a. The second detection electrodes 23A are arrayedin the direction along the short side of the display area 10 a, whereasthe second detection electrodes 23B are arrayed in the direction alongthe long side of the display area 10 a. The second detection electrodes23A and 23B are arranged in a manner surrounding the display area 10 a.The second detection electrodes 23A and 23B simply need to surround atleast two sides of the display area 10 a. The second detectionelectrodes 23A and 23B each have a rectangular shape. A plurality ofsecond detection electrodes 23A are arrayed along one drive electrodeCOML. The length of the long side of the second detection electrode 23Ais shorter than the length of the drive electrode COML in the extendingdirection.

In FIG. 28, the drive electrode driver 14 is provided on the short sideof the frame area 10 b near the display control IC 19. The arrangementof the drive electrode driver 14 is not limited thereto, and the driveelectrode driver 14 may be provided on the long side of the frame area10 b.

As illustrated in FIG. 29, the first detection electrodes TDL areprovided in the display area 10 a of the second substrate 31. The firstdetection electrodes TDL each include a plurality of metal wires 33 aand 33 b. The metal wires 33 a and 33 b each have a plurality of bendsand are formed into zigzag lines or wavy lines. The metal wires 33 a and33 b extend in the direction along the long side of the display area 10a. The metal wires 33 a and 33 b are separated by slits SLa and theslits SLa are formed at positions indicated by the dotted lines C inFIG. 29. The metal wires 33 a and 33 b separated by the slits SLafunction as one first detection electrode TDL.

The first detection electrodes TDL extend in the direction along thelong side of the display area 10 a and are arrayed in the directionalong the short side of the display area 10 a as a whole. The firstdetection electrodes TDL are coupled to the frame wire 37 at the end onthe short side of the display area 10 a and coupled to the touchdetection IC 18 mounted on the flexible substrate 71.

The second detection electrodes 23A and 23B according to the presentembodiment are also provided around the display area 10 a, and they eachdetect pressure. With this configuration, the present embodiment canaccurately detect the pressure. The second detection electrodes 23A arearrayed at least along the extending direction of the drive electrodesCOML. With this configuration, the present embodiment can accuratelydetect pressure distribution in a direction along the extendingdirection of the drive electrodes COML. An input position is detected bythe drive electrodes COML and the first detection electrodes TDL. Basedon the information on the input position and the information onpressure, the present embodiment can calculate the pressure applied atone or a plurality of input positions.

The first detection electrodes TDL according to the present embodimentmay also be arranged in a manner superimposed on the second detectionelectrodes 23A and 23B to function as a shielding layer in pressuredetection. As illustrated in FIG. 30, the first detection electrodes TDLeach have the first portion TDLa and the second portion TDLb. The firstportion TDLa mainly functions as the detection electrode in touchdetection, whereas the second portion TDLb functions as a shield thatblocks the fringing electric field Ef. The second portions TDLb arearranged near the short side of the display area 10 a, and the seconddetection electrodes 23A are provided at positions under the secondportions TDLb. With this configuration, the present embodiment candetect pressure while suppressing reduction in the touch detectionsensitivity.

As illustrated in FIG. 30, the second detection electrodes 23A and 23Bare coupled to the coupling wire 38 through respective contact holes H4.The coupling wire 38 is coupled to the drive electrode scanning unit 14a. In this case, the pixel signal lines SGL (refer to FIG. 25) may alsoserve as the coupling wire 38. With this configuration, the presentembodiment need not add another coupling wire 38, thereby suppressing anincrease in the number of laminated layers.

While the preferred embodiments of the present invention have beendescribed above, the present invention is not limited to the embodimentsdescribed above. The content disclosed in the embodiments is merely anexample, and can be variously modified within the scope not departingfrom the gist of the present invention. Any modifications appropriatelymade within the scope not departing from the gist of the presentinvention naturally belong to the technical scope of the presentinvention.

The shape and the arrangement of the second detection electrodes 23, forexample, may be appropriately changed. While the second detectionelectrodes 23 are provided in a manner surrounding four sides of thedisplay area 10 a, any of the four sides may be provided with no seconddetection electrode 23. While the first detection electrodes TDL ismesh-like wiring including a plurality of metal wires, the structure ofthe first detection electrodes TDL is not limited thereto. The firstdetection electrodes TDL may be made of a translucent electricallyconductive material and have a rectangular shape, a strip shape, orother shapes similarly to the drive electrodes COML. While the touchpanel 30 performs touch detection based on the basic principle of mutualcapacitance touch detection, it may perform touch detection based on thebasic principle of self-capacitance touch detection.

What is claimed is:
 1. A detection device comprising: a substrate havingpixel electrodes in a display area, first electrodes configured todetect contact or proximity of an object in a first period andoverlapping the pixel electrodes in a plan view, and second electrodesconfigured to detect contact or proximity of an object in a secondperiod different from the first period; a third electrode overlappingthe first electrodes and the second electrodes in a plan view; aconductor overlapping the second electrodes in a plan view, thesubstrate being located between the conductor and the second electrodes;and a frame wire provided in a frame area positioned on an outer side ofthe display area and coupled to the third electrode, wherein, in thesecond period, a drive signal is supplied to at least one of the secondelectrodes, the third electrode is disposed in a layer different from alayer of the second electrodes; overlaps the second electrodes in avertical direction perpendicular to a main surface of the substrate, andis supplied with a guard signal that has a waveform synchronized withthe drive signal in the second period, the third electrode is disposedin the display area and has a first portion provided at a center of thedisplay area and a second portion, and in the vertical direction, (a)the conductor, (b) the second electrodes which are located along an edgeof the display area and at least one of which are supplied with thedrive signal in the second period, and (c) the second portion that isprovided between the first portion and the frame wire along the edge ofthe display area and that is supplied with the guard signal having thewaveform synchronized with the drive signal in the second period, arestacked in this order.
 2. The detection device according to claim 1,wherein the second electrodes are located in the display area.
 3. Thedetection device according to claim 1, wherein the second electrodes arelocated outside the display area.
 4. The detection device according toclaim 1, wherein the second electrodes are located along at least twosides of the display area.
 5. The detection device according to claim 1,wherein the contact or the proximity is detected: in the first period,on a basis of an electrostatic capacitor between the first electrodesand the third electrode; and in the second period, on a basis of anelectrostatic capacitor between the second electrodes and the conductor.6. The detection device according to claim 5, wherein the firstelectrodes and the third electrode do not detect the contact or theproximity in the second period.
 7. The detection device according toclaim 1, wherein the second electrodes are located at a same layer as alayer of the pixel electrodes.
 8. The detection device according toclaim 1, wherein the pixel electrodes are located at an opposite side ofthe second electrodes from the substrate.
 9. The detection deviceaccording to claim 1, wherein the first electrodes are located at anopposite side of the second electrodes from the substrate.
 10. Thedetection device according to claim 1, wherein the third electrode issupplied with a voltage having a fixed potential in the first period.11. The detection device according to claim 1, wherein the drive signalis sequentially supplied to the second electrodes in the second period.12. The detection device according to claim 1, further comprising adisplay panel with the substrate, wherein, in a display operationperiod: an image is displayed on a surface of the display panel; each ofthe pixel electrodes is supplied with a corresponding video image signalof the video image signals; and the first electrodes are supplied with acommon voltage.
 13. The detection device according to claim 12, whereina position of the object being in contact with or in proximity to thesurface is detected in at least one of the first period and the secondperiod.
 14. The detection device according to claim 12, wherein pressureapplied on the surface by the object is detected in the second period.15. The detection device according to claim 12, wherein the first periodcomprises a plurality of first periods, the second period comprises aplurality of second periods, the display operation period comprises aplurality of display operation periods, and one frame period of thedisplay panel includes the first periods, the second periods, and thedisplay operation periods.
 16. A detection device comprising: firstelectrodes in a first layer; second electrodes in a second layerdifferent from the first layer; a third electrode overlapping the firstand second electrodes in a plan view; a conductor overlapping the secondelectrodes in a plan view and located at an opposite side of the secondelectrodes from the third electrodes; and a frame wire provided in aframe area positioned on an outer side of a display area and coupled tothe third electrode, wherein: in a first period, the first electrodesand the third electrode detect contact or proximity of an object; and ina second period, the second electrodes and the conductor detect contactor proximity of an object and a drive signal is supplied to at least oneof the second electrodes, and the third electrode is disposed in a layerdifferent from a layer of the second electrodes, overlaps the secondelectrodes in a vertical direction perpendicular to a main surface ofthe substrate, and is supplied with a guard signal that has a waveformsynchronized with the drive signal in the second period, the thirdelectrode is disposed in the display area and has a first portionprovided at a center of the display area and a second portion, and inthe vertical direction, (a) the conductor, (b) the second electrodeswhich are located along an edge of the display area and at least one ofwhich are supplied with the drive signal in the second period, and (c)the second portion that is provided between the first portion and theframe wire along the edge of the display area and that is supplied withthe guard signal having the waveform synchronized with the drive signalin the second period, are stacked in this order.
 17. The detectiondevice according to claim 16, wherein, in the first period, the contactor the proximity is detected on a basis of an electrostatic capacitorbetween the first electrodes and the third electrode; and in the secondperiod, the contact or the proximity is detected on a basis of anelectrostatic capacitor between the second electrodes and the conductor,and the first electrodes and the third electrode do not detect thecontact or the proximity.
 18. The detection device according to claim16, wherein, in the first period, a position of the object being incontact with or in proximity to a main surface of the detection deviceis detected; and in the second period, pressure applied on a mainsurface of the detection device by the object is detected.
 19. Thedetection device according to claim 16, wherein the third electrode issupplied with a voltage having a fixed potential in the first period.